tabplot: Graphical display of a 2-way contingency table

Description

Entries in a table are plotted as rectangles proportional to the entry in the table. Width of rectangles are proportional to column totals, height proportional to entries within each column, hence areas are proportional to entries in the table.

Usage

tabplot( M,
         col,
      border = "black",
         lwd = 2,
     collabs = TRUE,
     rowlabs = NULL,
       equal = FALSE,
         las = 1,
        main = NULL,
    cex.main = 1.0,
       vaxis = FALSE )

Arguments

Two-way table

col

colors to use for coloring within each column. Defaults to a grayscale. May also be a function that takes an integer argument, as e.g. rainbow().

border

color of borders around rectangles.

lwd

width of the lines around rectangles.

collabs

should colums be labelled.

rowlabs

character "r" or "l": rows labelled on left or right side

equal

should colums be plotted of equal width? If yes a plot similar to that obtainable from barplot is the result.

las

how should labelling be rotated.

main

heading for the plot

cex.main

character expansion for the heading.

vaxis

should a vertical axis be drawn. If character it gives the side where it is drawn.

Value

NULL. The function is used for its sideeffects.

Details

The function offers a few more facilities for two-way tables than mosaicplot, but is restricted to two-way tables as input.

Examples

Run this code

b <- sample( letters[1:4], 300, replace=TRUE, prob=c(3,1,2,4)/10 )
a <- rnorm( 300 ) - as.integer( factor( b ) ) / 8
tb <- table( cut( a, -3:2 ), b )
tabplot( tb )
tabplot( tb, rowlabs="right", col=heat.colors )

# Very similar plots
ptb <- sweep( tb, 2, apply( tb, 2, sum ), "/" )
par( mfrow=c(2,2) )
barplot( ptb, space=0 )
tabplot( tb, equal=TRUE, lwd=1 )
tabplot( tb, equal=TRUE, lwd=1, rowlabs="l" )
tabplot( tb, equal=FALSE, lwd=1, rowlabs="l" )

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